Gas heat exchanger and condensate precooler



Jan. 2, 1951 c. T. ASHBY 2,536,342

GAS HEAT EXCHANGER AND CONDENSATE PRECOOLER Filed Dec. 8, 1947 i INVEN TOR.

Patented Jan. 2, 1951 GAS HEAT EXCHANGER AND CONDENSATE PRECOOLER Carl T. Ashby, Evansville, Ind., assignor to Serve], Inc., New York, N. Y., a corporationof Delaware Application December 8, 1947, Serial No. 790,342

3 Claims. 1

This invention relates to refrigeration and particularly to absorption refrigerating systems of the uniform pressure type.

It is an object-of this invention to provide an improved means for precooling liquid refrigerant en route from the condenser to the evaporator of an absorption refrigerating system.

The above and other objects and advantages will be more clearly understood from the following detailed description taken in connection with the accompanying drawing, wherein: T

Fig. 1 is a view diagrammatically illustrating a refrigerating system incorporating my invention;

Fig. 2 is a detailed sectional view of a specific arrangement of a precooler in accordance with my invention.

For purposes of'illustration, I have incorporated my invention in an absorption refrigerating system of the uniform pressure type, which system includes generally a generator I II, a condenser II, a pressure vessel l2, an evaporator ii, a gas heat exchanger l4, an absorber I5, a liquid heat exchanger l6 and conduits interconnecting said elements for flow of a refrigerating medium, an absorption solution and a pressure-equalizing gas. The svstem may be charged, for example, with a refrigerant-absorbent solution, such as ammonia and water, and with hydrogen as the inert pressure-equalizing gas.

The generator includes a substantially horizontal shell divided into a rich solution chamber IT, a weak solution chamber l8 and provided with a flue III which passes through the two chambers. A standpipe l9 opens into and projects upwardly from the weak solution chamber. The strong solution chamber I! is provided with a dome 20. A riser or vapor-lift conduit 2| projects into the dome 29 and has the opposite end thereof connected to the upper portion of the standpipe l9. A conduit 22, provided with an air cooled rectifier 23, connects the upper part of standpipe I9 with the upper or inlet end of the condenser II. The outlet end of the condenser is connected by a conduit 24 to a low-temperature section l3 of the evaporator.

Weak solution chamber l8 of the generator is connected by conduit 25, an inner passage 26 of liquid heat exchanger l6, and a conduit 21 to the upper part of the absorber IS. The lower part of the absorber is connected by an absorber vessel 28, a conduit 29, an outer passage 30 of the liquid heat exchanger, anda conduit 3| to the rich solution chamber I! of the generator.

The pper part of the absorber is connected by a conduit 32, an outer passage 33 of gas heat exchanger l4, and a conduit 34 to the gas inlet end of low-temperature section l3 of the evaporator. The gas outlet end of the low-temperature section of the evaporator is connected by a conduit 35 to a high-temperature section l3 of the evaporator, and the gas outlet end of the hightemperature section of the evaporator is connected by a conduit 36. an inner passage 31 of the gas heat exchanger, a conduit 38, and absorber vessel 28 to the lower part of the absorber. Pressure vessel I2 is connected at its upper end to conduit 24 by a conduit 39, and at its lower end the pressure vessel is connected to conduit 38 by a conduit 40. A drain conduit 4| leads from the outlet of evaporator section l3 to the inner passage of the gas heat exchanger.

In accordance with this invention, and as shown more clearly in Fig. 2, the conduit 24, which delivers liquid refrigerant from the condenser to low-temperature section I3 of the evaporator, is provided with a coiled portion 24* that is wound around and placed in good thermal contact with the upper part of the gas heat exchanger The upper part of the gas heat exchanger is provided with a plurality of perforated discs 42 which are arranged to provide a large heat transfer surface between the rich inert gas flowing through the gas heat exchanger and the liquid refrigerant flowing through the coil 24*.

With heat applied to the generator flue, as by a gas burner 43, refrigerant vapor is expelled from solution in the weak solution chamber l8 of the generator, which expelled vapor flows upwardly through the standpipe to the upper portion thereof. Refrigerant vapor is also expelled from solution in the rich solution chamber I! which vapor collects in the dome 20 and passes therefrom through vapor-lift conduit 2| lifting absorption solution from the rich solution chamber into the standpipe. The expelled vapor flows from the upper part of the standpipe through conduit 22 and rectifier 23 into the condenser ll wherein the refrigerant vapor is liquefied. The liquid refrigerant formed in the condenser flows through conduit 24 and coil 24 into a low-temperature section l3 of the evaporator wherein the liquid refrigerant flows counterfiow to weak inert gas that flows from conduit 34 through the evaporator, whereby the refrigerant evaporates and diffuses into the inert gas to produce a refrigerating effect.

The partially enriched inert gas flows from th low-temperature section of the evaporator through conduit 35 into the high-temperature section l3 wherein this partially enriched gas flows concurrently with liquid refrigerant that flows from the low to the high temperature section of the evaporator through drain conduit I3. The enriched mixture of inert gas and refrigerant vapor flows from the high-temperature section of the evaporator through conduit 36 into the upper part of the gas heat exchanger wherein this cold rich mixture of refrigerant vapor and inert gas picks up heat from the perforated discs 12 which discs in turn pick up heat from the liquid refrigerant flowing through coil 24, whereby the liquid refrigerant is precooled before entering the low-temperature section of the evaporator. The enriched inert gas then flows through the inner passage 31 of the gas heat e'xchanger and conduit 38 into absorber vessel 28, and from there the inert gas fiows upwardly through the absorber l5.

Absorption solution weak in refrigerant flows from conduit 21 into the upper part of the absorber, whereby the absorption solution absorbs the refrigerant vapor from the rich inert gas, and the inert gas stripped of refrigerant vapor flows from the upper part of the absorber through conduit 32, outer passage 33 of the gas heat exchanger, and conduit 34 back to the low-temperature section of the evaporator.

The enriched absorption solution flows from the lower end of the absorber into absorber vessel 28, and from there the enriched absorption solution flows through conduit 29, outer passage 30 of the liquid heat exchanger, and conduit 3| into the strong solution chamber I! of the generator. The absorption solution is lifted from the strong solution chamben of the generator by vapor-lift pump 2| into the standpipe 19, from whence this solution flows into the weak solution chamber I8 of the generator. The weak solution flows from chamber It through conduit 25, inner passage 26 of the liquid heat exchanger, and conduit 21 back to the upper part of the absorber.

As shown particularly in Fig. 2, the weak inert 4 gas is withdrawn from the gas heat exchanger through conduit 34 ata point below that at which the coil M is wrapped around the inlet or enlarged portion of the rich inert gas passage of the heat exchanger. With this arrangement the liquid refrigerant passing through coil 24* en route to the evaporator is precooled by the relatively cold rich inert gas before such gas passes in heat exchange relation with the relatively warm weak inert gas, thereby assuring ample precooling of the liquid refrigerant before such refrigerant enters the evaporator.

Having thus disclosed my invention I wish it understood that I do not desire to be limited to the specific structure illustrated and described. for obvious modifications may occur to persons skilled in the art.

What is claimed is:

1. In an absorption refrigerating system of the continuous cycle inert gas type, a tubular casing having in one end a chamber communicating with one end of a conduit located within said casing and formin therewith a heat exchanger, an inlet for gas'to said chamber, an outlet for gas from the other end of said conduit, an inlet for gas to said casing adjacent the outlet end of said conduit, an outlet for gas from said casing adjacent said chamber, and a conduit for liquid arranged in thermal contact with said casing ex- REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,181,528 Widell Nov. 28, 1939 2,321,113 Taylor June a, 1943 

